Canceling orders and purchase orders
If you have created an order with ProcessOrder, you may wish to cancel it at some later date. It is possible to cancel an order as long as the warehouse has not begun picking it.
To cancel an order, send in another ProcessOrder request like you did before, but set OrderOperation to Remove. If the system manages to cancel the order, the Success boolean field in the response will be set to true.
Canceling a purchase order is very similar to canceling an order. Send in a new ProcessInOrder request with InOrderOperation set to Remove. If the warehouse has started receiving goods on the purchase order, you will not be able to cancel it.